The embodiments described herein are related to closure devices for adjusting seat backs or seat cushions. It may be desirable to adjust a seat back or seat cushion to provide more comfort and/or support to the back and spine. This may be especially desirable where an individual sits in a seat for an extended period of time. Non-adjustable seat back or seat cushions may become uncomfortable over time due to the creation of pressure points and the like, or due to the seat back or seat cushion not being properly fit or configured to the unique shape or contour of a user's back. An adjustable seat back or seat cushion may greatly reduce or relieve such discomfort, especially when the adjustment mechanism is convenient and easy to use. An especially advantageous use of an adjustable seat back or seat cushion may be in instances where an individual is confined to a wheel chair for an indefinite, prolonged, or permanent period of time.